System and method for exchanging heat

ABSTRACT

A system for exchanging heat includes a plurality of adjacent envelopes, wherein each envelope defines a plurality of volumes. A connection between adjacent envelopes provides fluid communication between the volumes in adjacent envelopes, and a fluid passage outside of the envelopes and defined by adjacent envelopes extends across a dimension of the system. A method for exchanging heat includes flowing a plurality of secondary fluids through a plurality of volumes in adjacent envelopes, wherein each secondary fluid flows through a separate volume in each envelope. The method further includes flowing a primary fluid through a plurality of channels outside of the adjacent envelopes and defined by the adjacent envelopes.

FIELD OF THE INVENTION

The present invention generally involves a system and method for exchanging heat. In particular embodiments, the system and method will enable an ambient fluid to simultaneously exchange heat with multiple system fluids flowing through a single heat exchanger.

BACKGROUND OF THE INVENTION

Many types of heat exchangers exist for transferring heat between fluid systems. For example, a heat exchanger of some type is included in almost every power generation device, ventilation, and water system used in the developed world, and virtually every automobile, truck, boat, aircraft, or other machine having a combustion engine, a pneumatic system, a hydraulic system, or other heat generating component includes at least one heat exchanger. In some applications, multiple heat exchangers may be used to exchange heat with multiple fluids, including air and gases. For example, an engine compartment of an automobile may include one heat exchanger to cool radiator fluid, a second heat exchanger to cool transmission fluid, and a third heat exchanger to cool refrigerant associated with an air conditioner. As another example, turbo diesel engine vehicles may include heat exchangers to cool and/or heat exhaust gases for better gas mileage or generation of electric power with a separate heat exchanger for an intercooler, exhaust gas recirculator, and/or turbo-electric generator. Larger vehicles may include additional heat exchangers to cool other hydraulic fluids, compressed air, or auxiliary systems. Each separate heat exchanger requires a separate footprint that occupies the finite available space in the engine compartment, increases manufacturing and maintenance costs, and adds to the overall weight of the vehicle. In addition, many heat exchangers have a generally accepted best location identified where this cooling and/or heating should take place based on the general design considerations and/or velocity of the air flow for heat exchange.

Various attempts have been made to reduce the costs associated with multiple heat exchangers by developing a single heat exchanger capable of exchanging heat with multiple fluids. For example, U.S. Pat. Nos. 5,462,113 and 5,964,114 describe multi-fluid heat exchangers that include a series of stacked plates. The stacked plates are arranged and sealed to produce multiple fluid passages inside the stacked assembly, and a different fluid may be supplied through each fluid passage to exchange heat with the other fluids flowing inside the stacked assembly. Although suitable for exchanging heat between the multiple fluids, these stacked assemblies do not allow or severely limit the surface area of the heat exchanger that is exposed to ambient fluids, such as air or water. As a result, these multi-fluid heat exchangers are unable to take full advantage of the relatively unlimited ambient heat removal that is generally available. Therefore, an improved heat exchanger that can more effectively utilize ambient fluids to remove heat from multiple system fluids would be useful.

BRIEF DESCRIPTION OF THE INVENTION

Aspects and advantages of the invention are circuit forth below in the following description, or may be obvious from the description, or may be learned through practice of the invention.

One embodiment of the present invention is a system for exchanging heat. The system includes a plurality of adjacent envelopes, wherein each envelope defines a plurality of volumes. A connection between adjacent envelopes provides fluid communication between the volumes in adjacent envelopes, and a fluid passage outside of the envelopes and defined by adjacent envelopes extends across a dimension of the system.

Another embodiment of the present invention is a system for exchanging heat that includes a plurality of envelopes arranged in layers, wherein each envelope defines a plurality of volumes. A channel between adjacent envelopes provides fluid communication across a dimension of the system.

The present invention may also include a method for exchanging heat that includes flowing a plurality of secondary fluids through a plurality of volumes in adjacent envelopes, wherein each secondary fluid flows through a separate volume in each envelope. The method further includes flowing a primary fluid through a plurality of channels outside of the adjacent envelopes and defined by the adjacent envelopes.

Those of ordinary skill in the art will better appreciate the features and aspects of such embodiments, and others, upon review of the specification.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including the best mode thereof to one skilled in the art, is set forth more particularly in the remainder of the specification, including reference to the accompanying figures, in which:

FIG. 1 is a perspective view of a system according to one embodiment of the present invention;

FIG. 2 is an exploded view of an exemplary envelope shown in FIG. 1;

FIG. 3 is a perspective view of a single envelope according to an alternate embodiment of the present invention; and

FIG. 4 is a partial perspective view of multiple envelopes stacked according to an alternate embodiment.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to present embodiments of the invention, one or more examples of which are illustrated in the accompanying drawings. The detailed description uses numerical and letter designations to refer to features in the drawings. Like or similar designations in the drawings and description have been used to refer to like or similar parts of the invention.

Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that modifications and variations can be made in the present invention without departing from the scope or spirit thereof. For instance, features illustrated or described as part of one embodiment may be used on another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.

Various embodiments of the present invention provide a system and method that allows an ambient fluid to simultaneously exchange heat with multiple system fluids flowing through a single heat exchanger. The systems and methods described herein may transfer heat to or from the ambient fluid. In particular embodiments, each system fluid flows through a dedicated volume or chamber inside the heat exchanger, and each dedicated volume or chamber has a surface exposed to the ambient fluid to exchange heat with the ambient fluid. Although particular embodiments of the present invention may be described in the context of an automobile, truck, or other vehicle, one of ordinary skill in the art will readily appreciate that the present invention is not limited to any particular application and may be suitably adapted for use in any application requiring the transfer of heat between fluids.

FIG. 1 provides a perspective view of a system 10 according to one embodiment of the present invention. As shown, the system 10 generally includes a plurality of envelopes 12 stacked on top of one another or arranged in layers to form a heat exchanger core 14. Each envelope 12 defines a plurality of volumes or cavities, and each volume or cavity includes an inlet and an outlet. For example, in the specific embodiment shown in FIG. 1, each envelope 12 defines five separate volumes 16, 18, 20, 22, 24. Each volume has an associated inlet and outlet, indicated by the arrows in FIG. 1, to provide five separate pathways for five separate system fluids to flow into and through the heat exchanger core 14.

As shown in FIG. 1, the layers of envelopes 12 define a fluid passage or channel 26 outside of and between adjacent envelopes 12. The multiple fluid passages or channels 26 extend across a dimension of the system 10. In this manner, a flow of ambient fluid 28, such as air or water, may flow through the fluid passages or channels 26 and around the layers of envelopes 12 to exchange heat with the system fluids flowing through the envelopes 12.

FIG. 2 provides an exploded view of an exemplary envelope 12 shown in FIG. 1. As shown, each envelope 12 generally includes a first section 30 joined to a second section 32 to define each volume in the envelope 12. For example, one or more weld beads, braze joints, or other impermeable barriers between the first and second sections 30, 32 may provide a seal 34 that defines each volume in each envelope 12. As shown in FIG. 2, adjacent volumes in each envelope 12 (e.g., volumes 18, 20, and 22) may be arranged parallel to the flow of ambient fluid 28 through the fluid passages or channels 26. Alternately, or in addition, adjacent volumes in each envelope 12 (e.g., volumes 16 and 18 or 22 and 24) may be arranged perpendicular to the flow of ambient fluid 28 through the fluid passages or channels 26. As further shown in FIGS. 1 and 2, the first and/or second sections 30, 32 may include a corrugated surface 36 and/or turbulators to disrupt the laminar fluid flow inside the envelopes 12 and/or through the fluid passages 26.

The particular materials, dimensions, shapes, and number of envelopes 12, corrugations, and turbulators will vary according to the particular application. For example, aluminum, copper, stainless steel, nickel, titanium, and other conductive metals, alloys, and superalloys provide suitable materials for the first and second sections 30, 32. The first and second sections 30, 32 may have a thickness of approximately 0.05-0.3 millimeters, and the corrugations or turbulators (if present) may have a height of approximately 2.5-10 millimeters. Alternately, the height of the corrugations or turbulators may be approximately ½ of the total thickness of an individual envelope 12. In still further embodiments, the height of the corrugations or turbulators may be less than ½ of the total thickness of an individual envelope 12 to produce larger fluid passages or channels 26 between adjacent envelopes 12. Each heat exchanger core 14 may include 100-500 layers of envelopes 12, or more or fewer layers of envelopes 12 if desired. One of ordinary skill in the art will readily appreciate that the particular materials, dimensions, shapes, and number of envelopes 12, corrugations, and turbulators are not limitations of the present invention unless specifically recited in the claims.

FIG. 3 provides a perspective view of an exemplary envelope 12 according to an alternate embodiment of the present invention. In this particular embodiment, the envelope 12 includes two distinct volumes 16, 18, and one volume (i.e., volume 16) substantially surrounds the second volume (i.e., volume 18). This particular arrangement may be used, for example, to regulate the exit temperatures of the system fluids flowing through the first and second volumes 16, 18.

FIG. 4 provides a partial perspective view of multiple envelopes 12 stacked together according to an alternate embodiment. As shown, a flange 40, lip, or other suitable structure coincident with the respective inlets and outlets for each volume may provide a connection between adjacent envelopes 12 that provides fluid communication between the volumes in adjacent envelopes 12. The adjacent and connected inlets and outlets may thus define a supply header 42 and an exhaust header 44, respectively, for each volume. Each system fluid may thus flow into a separate supply header 42, through the associated volume, and out the associated exhaust header 44. In the particular embodiment shown in FIG. 4, one or more of the corrugated surfaces 36 may be formed from substantially circular corrugations, and in some applications a weld seam placed at the troughs of corrugations, to increase the pressure capability of the associated volume. As a result, separate fluids having various system pressures may flow through the various volumes, and the flow of ambient fluid 28 through the fluid passages or channels 26 outside of and between the adjacent envelopes 12 exchanges heat with the system fluids flowing through the envelopes 12.

The various embodiments shown in FIGS. 1-4 may also provide a method for exchanging heat that includes flowing multiple secondary fluids through multiple volumes in adjacent envelopes 12, wherein each secondary fluid flows through a separate volume in each envelope 12. The method may further include flowing a primary fluid, such as ambient air or water, through multiple fluid passages or channels 26 outside of the adjacent envelopes 12 and defined by the adjacent envelopes 12. In particular embodiments, the method may include flowing the secondary fluids through the volumes parallel to and/or perpendicular to flow through the fluid passages or channels 26. In other particular embodiments, the method may include flowing a first secondary fluid through a first volume, wherein the first volume is surrounded by a second volume containing a second secondary fluid.

The various systems and methods described herein thus enable heat transfer to or from the ambient fluid to multiple secondary or system fluids in a single heat exchanger core 14. As a result, the single heat exchanger core 14 may replace multiple heat exchangers to reduce the footprint and/or weight of the multiple heat exchangers, change the location of the heat exchangers, and/or reduce manufacturing, assembly, and maintenance costs associated with the multiple heat exchangers.

This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims. 

1. A system for exchanging heat, comprising: a. a plurality of adjacent envelopes, wherein each envelope defines a plurality of volumes; b. a connection between adjacent envelopes that provides fluid communication between the volumes in adjacent envelopes; and c. a fluid passage outside of the envelopes and defined by adjacent envelopes, wherein the fluid passage extends across a dimension of the system.
 2. The system as in claim 1, wherein each envelope includes a first section joined to a second section to define each volume in each envelope.
 3. The system as in claim 1, wherein adjacent volumes in each envelope are arranged parallel to flow through the fluid passage.
 4. The system as in claim 1, wherein adjacent volumes in each envelope are arranged perpendicular to flow through the fluid passage.
 5. The system as in claim 1, wherein a first volume in each envelope is substantially surrounded by a second volume in each envelope.
 6. The system as in claim 1, wherein each envelope includes a corrugated surface.
 7. The system as in claim 1, wherein the plurality of adjacent envelopes defines a supply header and an exhaust header for each volume.
 8. A system for exchanging heat, comprising: a. a plurality of envelopes arranged in layers, wherein each envelope defines a plurality of volumes; and b. a channel between adjacent envelopes, wherein the channel provides fluid communication across a dimension of the system.
 9. The system as in claim 8, further comprising a connection between adjacent envelopes that provides fluid communication between the volumes in adjacent envelopes.
 10. The system as in claim 8, wherein each envelope includes a first section joined to a second section and a seal between the first and second sections defines each volume in each envelope.
 11. The system as in claim 8, wherein the plurality of volumes in each envelope is arranged parallel to flow through the plurality of channels.
 12. The system as in claim 8, wherein the plurality of volumes in each envelope is arranged perpendicular to flow through the plurality of channels.
 13. The system as in claim 8, wherein a first volume in each envelope is substantially surrounded by a second volume in each envelope.
 14. The system as in claim 8, wherein each envelope includes a turbulator.
 15. The system as in claim 8, wherein the plurality of envelopes defines a supply header and an exhaust header for each volume.
 16. A method for exchanging heat, comprising: a. flowing a plurality of secondary fluids through a plurality of volumes in adjacent envelopes, wherein each secondary fluid flows through a separate volume in each envelope; and b. flowing a primary fluid through a plurality of channels outside of the adjacent envelopes and defined by the adjacent envelopes.
 17. The method as in claim 16, further comprising flowing the plurality of secondary fluids through the plurality of volumes, wherein the plurality of volumes in each envelope is arranged parallel to flow through the channels.
 18. The method as in claim 16, further comprising flowing the plurality of secondary fluids through the plurality of volumes, wherein the plurality of volumes in each envelope is arranged perpendicular to flow through the channels.
 19. The method as in claim 16, further comprising flowing a first secondary fluid through a first volume, wherein the first volume is surrounded by a second volume containing a second secondary fluid. 